A light bulb includes: a bulb holder, a base, a lampshade, and an LED bulb panel. A lower end of the base is connected to the bulb holder. An upper end of the base is connected to the lampshade. The LED bulb panel is disposed on the base. A metal ring is sleeved on the lower end of the base. A first contact and a second contact are disposed on the bulb holder. A first light-emitting circuit and a second light-emitting circuit are disposed on the LED bulb panel. The metal ring is electrically connected to a first end of the first light-emitting circuit and a first end of the second light-emitting circuit. The first contact is electrically connected to a second end of the first light-emitting circuit. The second contact is electrically connected to a second end of the second light-emitting circuit.